Means for preventing the generation of static electricity in moving-picture apparatus.



G. W. NUSBAUM.

MEANS FOR PREVENTING THE GENERATION OF STATIC ELEIJTRICIIY IN MOVING PICTURE APPARATUS. I APPLICATION FILED AUGJ, 19M.

1,206,357 Paten tdfiovI 28, 1916.

igfa C i 1 E A A i 4 QwvenIo-z comm UNITED STATES OFFICE GEORGE W. NUSIBAUM, OF TAKOMA PARK, MARYLAND.

MEANS FOR PREVENTING THE GENERATION 0F STATIC ELECTRICITY IN MOVING- Application filed August 7, 1914.

To all'whom it may concern:

Be it known that I, Gnoucn W. NUSBAUM, a citizen of the United States, residing at Takoma Park, in the county of Montgomery ,and State of Maryland, have invented a new Means for Preventing the Generation of Static Electricity in Moving-Picture Apparetina, of which the following is a specification.

The object of my invention is to prevent the generation of static electricity by a movable dielectric member, such as the films used in moving picture apparatus.

In the accompanying drawing I have shown a sectional diagrammatic view of a moving picture camera in which my invention is embodied.

' In the drawing, A represents the framework of a moving picture camera, B rep resents a strip of dielectric material which is movable with respect to the framework The movable dielectric is guided in its movements by parts of the framework, such as guideways, rollers and other sur' faces which have a movable contact with the dielectric, and which are indicated on the drawing by the letter C. The dielectric member, in the device illustrated, is a film of sensitized celluloid such as commonly used in photographic work, but, of course, the specific material of which the dielectric is composed is immaterial; my invention being applicable to any dielectric.

It is well known that owing to the great speed of the film in moving picture apparatus, and the necessity for guiding surfaces, in contact with which the film moves, a large amount of static electricity is generated, and the sparks resulting from the discharge of the same affect the sensitized I surface and often ruin the entire film.

Various methods have been resorted to for the purpose of overcoming this difficulty and preventing the generation of static elec- PICTURE APPARATUS.

Specification of Letters Patent.

Patented N (W. 28, 1916.

Serial No. 855,581.

made of celluloid, the rollers and guides should be made of celluloid. My invention 1n its broad sense however, is not limited to material'having the same composition as the film but it is sufficient if the material used has the same electrical characteristics when subjected to friction.

My experiments have shown that it is not essential. that all. the surfaces in contact with the film be of the se me material as the film itself but that the use of such material for the parts of the apparatus as exert considerable pressure on the film is suflicient. 'lheoreticully, all surfaces in moving contact with the film should be of material having the same electrostatic characteristics as the film in order to entirely prevent the genera tion of static electricity but I have found that the amount of static electricity gener ated diminishes as the ratio of the bearing surfaces of such material, to the total bear ing surfaces, increases. Sincethe harmful effect of the static electricity is due to the lightfrom the discharges caused thereby, it is sufiicient if the tension of the static electricity be kept so low that discharges do not result, and this can be accomplished by properly proportioning the contact surfaces of the above mentioned material to any other suitable material.

Having explained my method, what I claim as my invention-or discovery and What 1 desire to secure by Letters Patent is:

1. In an apparatus of the class described, a frame, a dielectric member movable with respect to the frame and means for preventing the generation of static electricity by the moving dielectric, comprising surfaces in movable contact therewith of a material similar to the movable dielectric.

2. In an apparatus of the'class described, a frame, adielectric member movable with respect to the frame, andmeans for preventing the generation of static electricity by the movable dielectric, comprising surfaces in .movable contact therewith of the same ma- "a'frame, a dielectric member movable with i frame, and means for preventing the gem oration of static electricity by aid dielectric member, comprising surfac s in .u'mrablc contact therewith composed ol' material hav ing the same composition as the movable dielectric.

6. In an apparatus of the class rlcs *ribed, in con'ibination, a frame, a dielectric member movable with respect to the finale, and means for limiting the amount of static electrieity generated by said dielectric, comprising surfaces in morabie contact therewith composed of material having the same electrostatic characteristics when subjected to friction.

7. In an apparatus of the class described, a fran'ic, a celluloid film movable with respect to the frame, and means for limiting the amount of static electricity generated by the celluloid film, comprising surfaces of celluloid in movable contact therewith.

5. In a moving picture camera, a frame, a film of dielectric material movable with respect to the frame, :fnd means for limiting the amount of static electricity generated by said film, comprising guiding surfaces in movable contact with the film composed of material ha ring the. same electrostatic characteristics, when subjected to friction, as the 

